Christmas Bird Count 2018 wrap up:
Audubon’s 2018 Christmas Bird Counts (CBC) are in the books. During the month of December, hundreds of volunteer citizen scientists came together to find and compile a list of birds found within our region’s predetermined count circles.
Highlights from this year include:
The CBC program, in its 119th year, helps to shed light on local bird populations, expanding or retreating ranges of birds, and even how environmental factors may influence trends in bird demographics. The CBC was developed near the turn of the last century as an alternative to the annual bird hunt, that was conducted around Christmas time. Today, the CBC is the long-running and most inclusive data set on the continent.
In western Pennsylvania, several CBCs are conducted during the month of December. Each count is conducted during a specific 24-hour period, and within a specific 15-mile diameter circle. With data dating all the way back to 1910, the Pittsburgh count is by far the oldest count in the region. The Pittsburgh count was conducted on December 29th, 2018. 228 participants took part, which is the highest number of participants to date for this count. Within the Pittsburgh circle, which stretches from Schenley Park in the south, to North Park in the north; and from Kilbuck Township in the west, to Harmar in the east, participants spent a combined 433 party-hours, traveled 267 miles on foot, and 314 miles by car tallying birds. A grand total of 24,877 birds were recorded, representing 71 species.
Because of the large degree of participation, which contributes to a complete census of birds within the count circle, and the substantial amount of data contained in its history, the Pittsburgh CBC it is a good source from which to make comparisons of today’s bird numbers, versus bird numbers from yesteryear.
Some of the most obvious data comes when unusual bird species are found during the count.
Gadwall and Snow Goose are species that have been recorded on the count in the past. But the most recent Gadwall was found in 1994. We have to rewind all the way to 1988 to find the previous Snow Goose record.
Record high counts of birds are normally very easy to detect from year to year too. Red-breasted Mergansers have been found sporadically throughout the last couple of decades. They winter along the coasts, but can be found on area lakes and rivers when they are not frozen. This year, 7 were found on the Allegheny River, setting a new record high for the count.
Similarly, Turkey Vultures continue to be found on the Christmas count. Just 15 years ago,
Turkey Vultures were not even considered a possibility for the count. They are a migrant species that traditionally wintered in states south of Pennsylvania. And while most continue to migrate south, the species’ winter range is expanding north to include southwestern PA. 45 Turkey Vultures were tallied this year, falling just one individual short of tying the record.
17 Great-horned Owls ties the record for the most found during the count, set back in 1999.
11,126 American Crows were counted this year at their roost in Oakland. It is believed that there may be a secondary roost somewhere in Pittsburgh, which would explain the reason for a significant decrease in the individual numbers for this species. The high count was set in 2013 with a total of 32,913 individuals. American Crows roost colonially in winter, and are believed to select their roost locations based on factors that reduce predation while they rest. Counting them at their roost is an accurate way of determining overall numbers in a region.
In addition to American Crow, Fish Crow and Common Raven were found on count day. This marks the 6th year in a row that we have tallied all 3 corvid species in the Pittsburgh count circle.
Similarly, December’s count marks the 10th year in a row that we have found Winter Wren. 4 were detected for the count.
The tremendous amount of rain throughout the year has resulted in significant amount of natural food resources in our forests. This likely contributed to the impressive 576 Cedar Waxwings that were found during the count. They are being found regularly as they feed on available fruits in our area. Although not a record setting number, these findings were second to only 2007, when 778 individuals were found.
Many changes in nature happen in cyclical patterns. A good example is acorn mast from oak trees. We experience seasons when there are literally tons of acorns, and others when there are very few acorns. Much like oaks, conifers and birches go through these same cycles. When seed production is low, birds such as Purple Finches, Pine Siskins, Evening Grosbeaks and Common Redpolls depart the northern forests and move south in search of food resources. In early winter, reports came from the northern forests of pine seed and birch seed shortages. Therefore, it was expected that our Christmas Bird Count data would reflect an increase in the northern finch species. Surprisingly, that did not happen. Only 6 Pine Siskins and only 7 Purple Finches were found during the count. The northern birds have likely found resources farther north and have not made it far enough south to be found in our local counts.
Audubon Society of Western PA would like to extend its appreciation to everyone that participated in the CBC’s this season. It is only through your time and dedication that we can contribute to the understanding of our local bird populations. We, and the birds, thank you!